基于运动矢量的MPEG视频镜头边界检测

MPEG video shot boundary detection based on motion vectors

首先提取I帧的DC图进行镜头的粗略检测,然后提取P帧的前向运动补偿矢量,利用扩展矢量中值(EVM)滤波对运动矢量进行滤波预处理,并且进一步提取三个运动特征:运动强度值、运动强度差和运动矢量方向直方图绝对差,最后用模糊逻辑对上述三个特征进行综合,推理得出突变、渐变镜头和非镜头,实现镜头的检测。由于不需要对视频完全解压,直接从MPEG压缩码流中提取信息,所以计算复杂度低,提取速度较快。最后通过实验验证了该方法。

First, DC map of I frame was extracted for rough detection of the shots. And then the forward motion compensation vector of P frame was extracted, and Extended Vector Median （EVM） filtering was used for the preprocessing of motion vector. Finally the characteristics of three sports features, exercise intensity value, exercise intensity difference and the direction of motion vector histogram, absolute difference were calculated. Fuzzy inference was introduced to synthesize these three characteristics and classified shots to abrupt-change, gradual-change and no-change ones. The MPEG video shot boundary detection method do not need to decompress the video fully, and extracts information directly from MPEG compressed bit stream, so it is of low computation complexity and high extration speed, which is verified by the experimental results.